Micromechanical Semiconductor Sensing Device

ABSTRACT

Micromechanical semiconductor sensing device comprises a micromechanical sensing structure being configured to yield an electrical sensing signal, and a piezoresistive sensing device provided in the micromechanical sensing structure, said piezoresistive sensing device being arranged to sense a mechanical stress disturbing the electrical sensing signal and being configured to yield an electrical disturbance signal based on the sensed mechanical stress disturbing the electrical sensing signal.

This is a continuation application of U.S. application Ser. No.13/329,618, entitled “Micromechanical Semiconductor Sensing Device”which was filed on Dec. 19, 2011 and is incorporated herein byreference.

TECHNICAL FIELD

The invention relates to a micromechanical semiconductor sensing deviceand a method for manufacturing such a device. In particular, theinvention relates to a micromechanical semiconductor pressure sensingdevice and a method for manufacturing such a device.

BACKGROUND

In applications which involve low costs and the smallest possible spacerequirement, such as pressure sensors, microphones or accelerationsensors, miniaturized micromechanical semiconductor sensing devices areneeded.

As to such micromechanical semiconductor sensing devices, the mechanicaldisturbance stress acting on the device has an important influence onthe electrical output characteristic. The tensions within the packagingmaterial (e.g. mold compound) itself may be one possible reason formechanical disturbance stress. In particular, this problem appears withdifferent temperatures, because the mechanical disturbance stress variesstrongly with the temperature.

Appropriate measures for solving this problem are not known so far.

SUMMARY

An embodiment of the present invention provides a micromechanicalsemiconductor sensing device, comprising a micromechanical sensingstructure yielding an electrical sensing signal, and a piezoresistivesensing device provided in the micromechanical sensing structure, saidpiezoresistive sensing device being arranged to sense a mechanicalstress disturbing the electrical sensing signal thereby yielding anelectrical disturbance signal.

Another embodiment of the present invention provides a method formanufacturing such a micromechanical semiconductor sensing device,comprises the following steps: structuring a micromechanical sensingstructure for yielding an electrical sensing signal, and providing atleast one piezoresistive sensing device in the micromechanical sensingstructure, the piezoresistive sensing device being arranged to sense amechanical stress disturbing the electrical sensing signal therebyyielding an electrical disturbance signal.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of the present invention will now be described in detail withthe accompanying drawings, in which:

FIG. 1 a shows a block diagram of a micromechanical semiconductorsensing device according to an embodiment of the present invention.

FIG. 1 b shows a block diagram of a micromechanical semiconductorsensing device according to a further embodiment of the presentinvention.

FIG. 2 a shows a schematic view of an element of a micromechanicalsensing structure which is subject to mechanical disturbance stress,

FIG. 2 b shows a schematic view of an element of a micromechanicalsensing structure which is subject to an external selective force,

FIG. 3 shows a schematic view of the micromechanical sensing structureof a capacitive pressure sensor,

FIG. 4 shows a schematic view of a micromechanical semiconductor sensingdevice according to an embodiment of the present invention,

FIG. 5 a shows a schematic view of a pressure sensing device accordingto an embodiment of the present invention,

FIG. 5 b shows a schematic view of a pressure sensing device accordingto a further embodiment of the present invention,

FIG. 6 a shows a schematic view of an acceleration sensing deviceaccording to an embodiment of the present invention,

FIG. 6 b shows a schematic view of an acceleration sensing deviceaccording to a further embodiment of the present invention,

FIG. 7 shows a flow diagram of a method for manufacturing amicromechanical semiconductor sensing device according to an embodimentof the present invention, and

FIG. 8 shows a block diagram of a method for sensing an external forceon a device according to a further embodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 1 a shows a block diagram of a micromechanical semiconductorsensing device 100 according to an embodiment of the present invention.

The micromechanical semiconductor sensing device 100 comprises amicromechanical sensing structure 10 configured to yield (or provide) anelectrical sensing signal 15. The electrical sensing signal 15 maydescribe an external force on the micromechanical semiconductor sensingdevice 100, which is to be sensed with the micromechanical semiconductorsensing device 100. Furthermore, the micromechanical semiconductorsensing device 100 comprises a piezoresistive sensing device 14 providedin the micromechanical sensing structure 10. The piezoresistive sensingdevice 14 is arranged to sense a mechanical stress disturbing theelectrical sensing signal 15 and is configured to yield (or provide) anelectrical disturbance signal 16, based on the sensed mechanical stressdisturbing the electrical sensing signal 15.

The micromechanical semiconductor sensing device 100 enables that boththe electrical sensing signal 15 and the electrical disturbance signal16 can be collected within the micromechanical sensing structure 10.Hence, the mechanical disturbance stress which is measured by thepiezoresistive sensing device 14 is actually the mechanical disturbancestress acting on the micromechanical sensing structure 10, whichdisturbs the electrical sensing signal 15. Hence, the micromechanicalsemiconductor sensing device 100 enables not only a precise measurementof the electrical sensing signal 15 but also of the disturbance in thiselectrical sensing signal 15. Hence, the disturbance in the electricalsensing signal 15 can be compensated or eliminated based on the measuredelectrical disturbance signal 16. Furthermore, as the piezoresistivesensing device 14 is provided (e.g. integrated or buried) in themicromechanical sensing structure 10 even variations of the mechanicaldisturbance stress caused by temperature variations can be sensed andcompensated, due to the fact that both the piezoresistive sensing device14 and the micromechanical sensing structure 10 are subjected to thesame temperature variations.

Hence, the micromechanical semiconductor sensing device 100 has areliable protection against the mechanical disturbance stress acting onsuch micromechanical semiconductor sensing device 100.

The micromechanical sensing structure 10 may be integrated on a chip.

FIG. 1 b shows a block diagram of a micromechanical semiconductorsensing device 101 according to a further embodiment of the presentinvention.

The micromechanical semiconductor sensing device 101 differs from themicromechanical semiconductor sensing device 100 in that themicromechanical sensing structure 10 comprises a sensing element 11which is configured to yield, for example, via an electrical element 13the electrical sensing signal 15.

For example, the sensing element 11 can be a movable (pressure)diaphragm of a capacitive pressure sensor or a movable (acceleration)diaphragm of an acceleration sensor.

Furthermore, there is shown a stress element 12 which is subject ofmechanical disturbance stress. The piezoresistive sensing device 14 isburied in the stress element 12 and is configured to yield theelectrical disturbance signal 16.

The piezoresistive sensing device 14 may be e.g. a piezoresistor or astress-sensitive transistor.

According to some embodiments of the present invention themicromechanical sensing structure 10 comprises elements which are partof the micromechanical semiconductor sensing device and which are usedto convert an external selective force into the electrical sensingsignal 15. As an example, the micromechanical sensing structure 10 cancomprise or constitute a sensor (e.g. the sensing element 11), which isconfigured to convert an external selective force into the electricalsensing signal 15. According to embodiments such a sensor may be apressure sensor, a microphone or an acceleration sensor or any othersensor being capable of converting external selective forces intoelectrical sensing signals.

It is possible but not necessary that the sensing element 11 and thestress element 12 constitute the same element. For example, the sensingelement 11 can be a movable diaphragm of a capacitive pressure sensor ora movable diaphragm of an acceleration sensor, wherein at the same timethe movable diaphragm is used as the stress element 12 which is subjectof mechanical disturbance stress. The piezoresistive sensing device canbe placed in the middle of the diaphragm such that the piezoresistivesensing device senses as little as possible from the external selectiveforce to be measured but as much as possible from the mechanicaldisturbance stress.

Furthermore, the micromechanical semiconductor sensing device 101comprises a compensation logic 17 which is configured to compensate,based on the electrical disturbance signal 16, a disturbance in theelectrical sensing 15 signal caused by the mechanical stress. Or inother words, the electrical disturbance signal 16 of the piezoresistivesensing device 14 is used by the compensation logic 17 to eliminate theelectrical component of mechanical stress disturbing the electricalsensing signal 15. As an example, the compensation logic 17 may beconfigured to generate an output signal 18 based on a combination of theelectrical sensing signal 15 and the electrical disturbance signal 16.The resulting output signal 18 is less influenced by the mechanicaldisturbance stress than the electrical sensing signal 15 alone. As anexample, the compensation logic 17 may be configured to subtract theelectrical disturbance signal 16 from the electrical sensing signal 15,to remove the disturbance caused by mechanical stress from (or at leastto reduce the disturbance caused by mechanical stress in) the electricalsensing signal 15. Hence, the micromechanical semiconductor sensingdevice 101 enables that the electrical sensing signal 15 is a moreprecise representation of the external selective force measured by thesensing element 11 than with known sensing devices possible.

To summarize, at an output of the calibration logic 17 there is theoutput signal 18 which constitutes now an improved signal and which isless influenced by the mechanical disturbance stress.

The calibration logic 17 may be initialized during the calibration ofthe micromechanical semiconductor sensing device.

Having a capacitive pressure sensor, for example, it is possible toexpose the pressure sensor in a pressure chamber to various pressures.For each pressure, the capacity of the diaphragm is measured. Theresulting measurement signals can be used to determine calibrationcoefficients which can be stored in an internal storage of the pressuresensor.

The calibration both of the electrical sensing signal 15 and of theelectrical disturbance signal 16 can be achieved by exposing thepressure sensor to various temperatures and pressures. The result is anidentification field for different pressures and different temperatures.Now, the resulting measurement signals both of the electrical sensingsignal 15 and the electrical disturbance signal 16 can be used todetermine a two-dimensional field of calibration coefficients which canbe stored in an internal storage of the pressure sensor.

FIG. 2 a shows a schematic view of an element of a micromechanicalsensing structure which is subject to mechanical disturbance stress. Theelement 20 is supported by a support structure 21, 22. Mechanicaldisturbance stress acts on the element 20 in the directions 23, 24 andcauses internal tensions within the element 20.

FIG. 2 b shows a schematic view of an element of a micromechanicalsensing structure which is subject to an external selective force. Theelement 20 is again supported by a support structure 21, 22. Now, anexternal selective force 25 acts on the element 20 and causes adeformation of the element 20. The deformation can be measured by apiezoresistive sensing device wherein the piezoresistive sensing devicecan have e.g. the positions A, B or C. In reaction of the externalselective force 25, a piezoresistive sensing device measures in positionA a compression and in position C an expansion. However, a measurementin position B is virtually not influenced by the external selectiveforce 25. Nevertheless, a measurement in position B can still measuremechanical disturbance stress as shown in FIG. 2 a.

Hence, it is possible to position a piezoresistive sensing deviceaccording to the invention in an element of a micromechanical sensingstructure which selectively measures mechanical disturbance stresswithout being influenced by an external selective force which yields theactual electrical sensing signal of the micromechanical sensingstructure.

FIG. 3 shows a schematic view of the micromechanical sensing structureof a capacitive pressure sensor. The micromechanical sensing structureis mounted on a substrate 30. Usually, the substrate 30 is made ofsilicon. On the silicon substrate, a movable diaphragm 31 is shaped by aplurality of masking and etching steps. The movable diaphragm 31 isconductive or has at least a conductive coating on its surface. Thisconductive coating is connected via conductor lines with a measurementelectronic. On the opposite side of the movable diaphragm 31 there is anelectrode 32 made of a conductive coating, e.g. a metal or an alloy. Theelectrode 32 is also connected via conductor lines with the measurementelectronic. For example, the measurement electronic can be integrated onthe silicon substrate 30.

An external selective force acting on the movable diaphragm 31 causes adeformation. Accordingly, the height of the hollow space 33 will beincreased or decreased. The movable diaphragm 31 and the electrode 32constitute together a plate capacitor. The capacity of the platecapacitor depends on the distance between the movable diaphragm 31 andthe electrode 32. Hence, by measuring the capacity by means of ameasurement electronic, the external selective force (pressure,acceleration of a test mass, etc.) acting on the movable diaphragm 31can also be measured.

FIG. 4 shows a schematic view of a micromechanical semiconductor sensingdevice 400 according to an embodiment of the present invention. Themicromechanical semiconductor sensing device 400 comprises a housing 40,pins 41 and a chip substrate 42. Furthermore, a micromechanical sensingstructure 43 is mounted on the chip substrate 42.

FIG. 5 a shows a schematic view of a pressure sensing device 500according to the present invention. As an example, the pressure sensingdevice 500 may be an implementation of the micromechanical semiconductorsensing device 100 or the micromechanical semiconductor sensing device101.

Hence, the pressure sensing device 500 includes a movable diaphragm 51and a supporting structure made of a silicon substrate (not shown).Arranged above the substrate is a silicon counterelectrode 52. Thecounterelectrode 52 and the diaphragm 51 form a cavity 53 between thediaphragm 51 and the counterelectrode 52. The counterelectrode 52 andthe diaphragm 51 are designed to be conductive by suitable doping of thesilicon and are isolated from each other by an isolator 56 (e.g. by anisolation layer 56). Hence, the diaphragm 51, counterelectrode 52, andthe cavity 53 create a capacitor structure 54, with the counterelectrode52 and the diaphragm 51 acting as “capacitor plates” and the cavity 53acting as dielectric.

If the diaphragm 51 is exited to vibrate, the capacitance of thecapacitor structure 54 changes. The capacitance may be determined withthe aid of metal contacts arranged on the top of the structure.

As an example, the sensing element 11 may be connected to the diaphragm51 and the counterelectrode 52 and may be configured to sense thecapacitance of the capacitor structure 54 and to derive the electricalsensing signal 15 based on the sensed capacitance of the capacitorstructure 54.

The diaphragm material can be monocrystalline silicon.

In the middle of the diaphragm 51 a piezoresistor 55 is buried which isconfigured to yield the electrical disturbance signal 16. In otherwords, in the embodiment shown FIG. 5 a, the piezoresisitve sensingdevice 14 comprises or constitutes the piezoresistor 55. Piezoresistorscan be built into any rigid or flexible monocrystalline siliconstructure, making the measurement of strain in the structure possible.

As explained according to FIG. 2 a and FIG. 2 b, the piezoresistor 55(or piezoresisitve sensing device 14) can be placed in the diaphragm 51such to measure selectively the mechanical disturbance stress acting onthe pressure sensing device 500 whereas the external pressure acting onthe movable diaphragm 51 is measured based on variation of thecapacitance of capacitor structure 54 by the sensing element 11.

FIG. 5 b shows a schematic view of a pressure sensing device 501according to the present invention. As an example, the pressure sensingdevice 501 may be another implementation of the micromechanicalsemiconductor sensing device 100 or the micromechanical semiconductorsensing device 101.

The pressure sensing device 501 differs from the pressure sensing device500 in that a stress sensitive transistor 57 is used instead of thepiezoresistor 55. Otherwise, the explanations of FIG. 5 a apply also toFIG. 5 b, wherein the same reference signs are used for the elements.

FIG. 6 a shows a schematic view of an acceleration sensing device 600according to the present invention. As an example, the pressure sensingdevice 600 may be another implementation of the micromechanicalsemiconductor sensing device 100 or the micromechanical semiconductorsensing device 101

In principle, the acceleration is measured by a test mass 61 which ismounted on a spring 62, wherein the movement of the test mass ismeasured by a change of the capacitance of a capacitor 63 within acavity 64. As example, the sensing 11 element may be configured tomeasure the change of the capacitance of the capacitor 63, to derive theelectrical sensing signal 15.

To achieve this, the acceleration sensing device 600 can be realized bya deflectable pressure measuring diaphragm and a counter-structure. Thetest mass is connected 61 to the pressure measuring diaphragm in orderto be deflected from an idle position depending on an accelerationapplied. The deflection of the mass results in a change of the distancebetween the pressure measuring diaphragm and the counter-structure,which is detectable by a change of the capacitance of the capacitor 63.

Furthermore, the cavity 64 is supported by a support structure 65. Inthe middle of the support structure 65, a piezoresistor 66 is buriedyielding the electrical disturbance signal 16. Hence in the embodimentshown in FIG. 6 a, the piezoresistive sensing device 14 comprises orconstitutes the piezoresistor 66.

As explained according to FIG. 2 a and FIG. 2 b, the piezoresistor 66can be placed in the support structure 65 such to measure selectivelythe mechanical disturbance stress acting on the acceleration sensingdevice 600 whereas the acceleration acting on the test mass 61 ismeasured based on a change of the capacitance of the capacitor 63 by thesensing element 11.

FIG. 6 b shows a schematic view of an acceleration sensing device 601according to the present invention. As an example, the pressure sensingdevice 601 may be another implementation of the micromechanicalsemiconductor sensing device 100 or the micromechanical semiconductorsensing device 101. The acceleration sensing device 600 differs from theacceleration sensing device 601 in that a stress sensitive transistor 67is used instead of the piezoresistor 66. Otherwise, the explanations ofFIG. 6 a apply also to FIG. 6 b, wherein the same reference signs areused for the elements.

FIG. 7 shows a flow diagram of a method 700 for manufacturing amicromechanical semiconductor sensing device according to an embodimentof the present invention.

The method 700 comprises a step 701 of structuring a micromechanicalsensing structure configured to yield an electrical sensing signal.

Furthermore the method 700 comprises a step 702 of providing at leastone piezoresistive sensing device in the micromechanical sensingstructure, the piezoresistive sensing device being arranged to sense amechanical stress disturbing the electrical sensing signal and beingconfigured to yield an electrical disturbance signal based on the sensedmechanical stress disturbing the electrical sensing signal.

FIG. 8 shows a block diagram of a method 800 for sensing an externalforce on a device according to a further embodiment of the presentinvention.

The method 800 comprises a step 801 of simultaneously determining anelectrical sensing signal describing the external force and anelectrical disturbance signal describing mechanical stress on thedevice, the mechanical stress disturbing the electrical sensing signal.

Furthermore, the method 800 comprises a step 802 of compensating basedon the electrical disturbance signal a disturbance in the electricalsensing signal caused by the mechanical stress.

The method 800 may be performed by embodiments of the present invention,e.g. by the micromechanical semiconductor sensing device 101.

The method 800 may be supplemented by any features of the apparatusesdescribed herein.

To summarize, some embodiments of the present invention provide amicromechanical semiconductor sensing device and a method formanufacturing such a device with an additional measurement of themechanical stress acting on the device. To achieve this, someembodiments provide a piezoresistive sensing device in themicromechanical sensing structure, said piezoresistive sensing devicebeing arranged to sense a mechanical stress disturbing the electricalsensing signal thereby yielding an electrical disturbance signal.

According to further embodiments, the piezoresistive sensing device isarranged such to sense as little as possible from the quantity to bemeasured but as much as possible from the mechanical disturbance stress.It is also possible to provide several piezoresistive sensing devices atappropriate locations within the micromechanical sensing structure.

According to further embodiments, the piezoresistive sensing device is apiezoresistor or a stress-sensitive transistor. Piezoresistors can bebuilt into any rigid or flexible single-crystal silicon structure,making the measurement of strain in the structure possible. The sameapplies for stress-sensitive transistors.

According to further embodiments, the electrical disturbance signal ofthe piezoresistive sensing device is used by a compensation logic toeliminate the mechanical stress disturbing the electrical sensingsignal.

According to further embodiments, the micromechanical sensing structureconstitutes a capacitive pressure sensor with a movable diaphragm abovea hollow space. For example, the piezoresistive sensing device is buriedin the diaphragm.

According to further embodiments, the micromechanical sensing structureconstitutes an acceleration sensing device with an inertial elementinside a cavity, wherein the cavity is supported by a support structure.For example, the piezoresistive sensing device is buried in the supportstructure.

Some aspects of embodiments of the present invention shall be summarizedin the following.

Embodiments of the present invention solve the problem that a mechanicaldisturbance stress on a semiconductor sensing device can vary verystrongly for different temperatures by providing at every sensing cell(e.g. at every sensing element 11), e.g. a capacitive pressurediaphragm, an additional stress compensation by means of apiezoresistive sensing cell (e.g. the piezoresistive sensing device 14,e.g. the piezoresistive transistor 57, 67 or the piezoresistor 55, 66).The additional information of the piezoresistive signal (e.g. theelectrical disturbance signal 16), which is based on temperaturevariable mechanical stresses, can be used for eliminating parasiticinfluences by means of the compensation logic 17.

In some embodiments of the present invention the electricalcompensation, e.g. at a capacitive pressure sensor, is achieved byimplementing the piezoresistive transistor or the piezoresistor in apressure diaphragm (e.g. the pressure diaphragm 51, 65) or the pressurediaphragms of the capacitive pressure sensor. Based on the electricalsignals of the piezoresistive part (e.g. based on the electricaldisturbance signal 16) mechanical stresses which have a massivelynegative influence on the calibration of the sensor can be determinedadditionally to the capacitive part (e.g. the electrical sensing signal15). Some embodiments of the present invention are configured todetermine for every time the electrical sensing signal 15 (thecapacitive part) is determined simultaneously the electrical disturbancesignal 16 (the piezoresistive part) directly at the sensing element 11(e.g. at the pressure diaphragm). The additional information of thepiezoresistive signal (of the electrical disturbance signal 16) can beused for eliminating parasitic influences by means of the compensationlogic 17.

According to some embodiments of the present invention a pressurediaphragm (e.g. the sensing element 11) and the piezoresistive elements(e.g. the piezoresistive sensing device 14) may comprise monocrystallinesilicon or even may be constituted of monocrystalline silicon. Apiezoresistive or stress sensitive transistor (e.g. the transistor 57,67) can be formed by means of implants. Low ohmic terminals can beformed, for example, by means of silicid.

According to some embodiments of the present invention thepiezoresistive sensing device 14 (e.g. the mentioned piezoresistor orthe mentioned stress sensitive transistor) may be placed in differentdepths of the diaphragm (e.g. in the middle of the diaphragm) forminimizing the piezoresistive part of the electrical disturbance signal16 which is based on a deflection of the diaphragm (caused by pressurevariations) which is in this case not relevant to the sensing.

According to further embodiments of the present invention amicromechanical semiconductor sensing device may comprise a plurality ofpiezoresistive sensing devices which are arranged at different positionsin the micromechanical sensing structure (e.g. at different positions ofthe sensing element 11).

Hence, some embodiments of the present invention comprise in everymicromechanical sensing structure (e.g. in every pressure diaphragmcell) an additional stress sensitive transistor or piezoresistor fordetection of mechanical stress. The stress sensitive transistor orpiezoresistor can be connected to a compensation logic such thatparasitic stress influences (e.g. the mechanical stress disturbing theelectrical sensing signal) on the electrical sensing signal can beeliminated (e.g. at the capacitive pressure sensor).

The stress compensation described above may be used especially withstandard packages, as these are typically not stress optimized.

The above described embodiments are merely illustrative for theprinciples of the present invention. It is understood that modificationsand variations of the arrangements and the details described herein willbe apparent to others skilled in the art. It is the intent, therefore,to be limited only by the scope of the impending patent claims and notby the specific details presented by way of description and explanationof the embodiments herein.

Although some aspects have been described in the context of anapparatus, it is clear that these aspects also represent a descriptionof the corresponding method, where a block or device corresponds to amethod step or a feature of a method step. Analogously, aspectsdescribed in the context of a method step also represent a descriptionof a corresponding block or item or feature of a correspondingapparatus. Some or all of the method steps may be executed by (or using)a hardware apparatus, like for example, a microprocessor, a programmablecomputer or an electronic circuit. In some embodiments, some one or moreof the most important method steps may be executed by such an apparatus.

What is claimed is:
 1. A micromechanical semiconductor sensing devicecomprising: a micromechanical sensing structure configured to output anelectrical sensing signal responsive to an external force on themicromechanical semiconductor sensing device; and a piezoresistivesensing device provided in the micromechanical sensing structure, thepiezoresistive sensing device configured to sense a mechanical stress inthe micromechanical sensing structure due to the external force on themicromechanical semiconductor sensing device, and configured to outputan electrical disturbance signal responsive to the sensed mechanicalstress.
 2. The micromechanical semiconductor sensing device according toclaim 1, further comprising a compensation logic configured tocompensate, based on the electrical disturbance signal, a disturbance inthe electrical sensing signal caused by the mechanical stress.
 3. Themicromechanical semiconductor sensing device according to claim 1,wherein the micromechanical sensing structure comprises a capacitivepressure sensor with a movable diaphragm above a hollow space.
 4. Themicromechanical semiconductor sensing device according to claim 1,wherein the micromechanical sensing structure comprises an accelerationsensing device with an inertial element inside a cavity, wherein thecavity is supported by a support structure.
 5. A method formanufacturing a micromechanical semiconductor sensing device, the methodcomprising: structuring a micromechanical sensing structure foroutputting an electrical sensing signal responsive to an external forceon the micromechanical semiconductor sensing device; and providing atleast one piezoresistive sensing device in the micromechanical sensingstructure for sensing a mechanical stress in the micromechanical sensingstructure due to the external force on the micromechanical semiconductorsensing device, and for outputting an electrical disturbance signalresponsive to the sensed mechanical stress.
 6. The method according toclaim 5, wherein the micromechanical sensing structure is structured asa capacitive pressure sensor with a movable diaphragm above a hollowspace.
 7. The method according to claim 5, wherein the micromechanicalsensing structure is structured as an acceleration sensing device withan inertial element inside a cavity, wherein the cavity is supported bya support structure.
 8. A micromechanical semiconductor sensing devicecomprising: a micromechanical sensing structure configured to output anelectrical sensing signal responsive to an external force on themicromechanical semiconductor sensing device; and means for sensing amechanical stress in the micromechanical sensing structure due to theexternal force on the micromechanical semiconductor sensing device; andmeans for outputting an electrical disturbance signal responsive to thesensed mechanical stress, wherein the means for sensing the mechanicalstress and the means for outputting the electrical disturbance signalare provided in the micromechanical sensing structure.
 9. A method forsensing an external force on a micromechanical semiconductor sensingdevice, the method comprising: simultaneously determining an electricalsensing signal and an electrical disturbance signal from amicromechanical sensing structure of the micromechanical semiconductorsensing device, the electrical sensing signal being responsive to anexternal force on the micromechanical semiconductor sensing device, andthe electrical disturbance signal being responsive to a mechanicalstress in the micromechanical sensing structure due to the externalforce on the micromechanical semiconductor sensing device; andcompensating based on the electrical disturbance signal a disturbance inthe electrical sensing signal caused by the mechanical stress.